Deep Brain Stimulation
Philip A. Starr, Nicholas M. Barbaro, Neil H. Raskin and Jill L. Ostrem
Cluster headache (CH) is the most severe of the primary headache disorders. Based on the finding that regional cerebral blood flow is increased in the ipsilateral posterior hypothalamic region during a CH attack, a novel neurosurgical procedure for CH was recently introduced: hypothalamic deep brain stimulation (DBS). Two small case series have been described. Here, the authors report their technical approach, intraoperative physiological observations, and 1-year outcomes after hypothalamic DBS in four patients with medically intractable CHs.
Patients underwent unilateral magnetic resonance (MR) imaging–guided stereotactic implantation of a Medtronic DBS (model 3387) lead and Soletra pulse generator system. Intended tip coordinates were 3 mm posterior, 5 mm inferior, and 2 mm lateral to the midcommissural point. Microelectrode recording and intraoperative test stimulation were performed. Lead locations were measured on postoperative MR images. The intensity, frequency, and severity of headaches throughout a 1-week period were tracked in patient diaries immediately prior to surgery and after 1 year of continuous stimulation.
At the 1-year follow-up examination, DBS had produced a greater than 50% reduction in headache intensity or frequency in two of four cases. Active contacts were located 3 to 6 mm posterior to the mammillothalamic tract. Neurons in the target region showed low-frequency tonic discharge.
In two previously published case series, headache relief was obtained in many but not all patients. The results of these open-label studies justify a larger, prospective trial but do not yet justify widespread clinical application of this technique.
Philip A. Starr, Robert S. Turner, Geoff Rau, Nadja Lindsey, Susan Heath, Monica Volz, Jill L. Ostrem and William J. Marks Jr.
Deep brain stimulation (DBS) of the globus pallidus internus (GPI) is a promising new procedure for the treatment of dystonia. The authors describe their technical approach for placing electrodes into the GPI in awake patients with dystonia, including methodology for electrophysiological mapping of the GPI in the dystonic state, clinical outcomes and complications, and the location of electrodes associated with optimal benefit.
Twenty-three adult and pediatric patients with various forms of dystonia were included in this study. Baseline neurological status and DBS-related improvement in motor function were measured using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). The implantation of DBS leads was performed using magnetic resonance (MR) imaging–based stereotaxy, single-cell microelectrode recording, and intraoperative test stimulation to determine thresholds for stimulation-induced adverse effects. Electrode locations were measured on computationally reformatted postoperative MR images according to a prospective protocol.
Physiologically guided implantation of DBS electrodes in patients with dystonia was technically feasible in the awake state in most patients, and the morbidity rate was low. Spontaneous discharge rates of GPI neurons in dystonia were similar to those of globus pallidus externus neurons, such that the two nuclei must be distinguished by neuronal discharge patterns rather than rates. Active electrode locations associated with robust improvement (> 70% decrease in BFMDRS score) were located near the intercommissural plane, at a mean distance from the pallidocapsular border of 3.6 mm.